“Skin disinfectants” are routinely used in professional and non-professional contexts to rapidly kill microbes. A physician has a need to disinfect his or her skin both before and after examining a patient. Prior to the performance of an invasive medical procedure, the skin of the subject must be properly cleaned to avoid post-procedure infections. In non-professional contexts, a commuter, riding public transportation, may wish to disinfect her hands before handling food; a child, playing in a park, may need to clean his hands but not have the convenience of soap and water nearby. Each of these situations require, optimally, a skin disinfectant that is effective, easy to use, and non-irritating so as to permit repeated use.
A number of skin disinfectants have been developed that use alcohol as the primary antimicrobial agent. There are two general problems associated with alcohol-based disinfectants. First, the effective concentration of alcohol, generally regarded to be greater than about 60 percent weight (hereafter, all percentages should be considered weight/volume percentages, unless specified otherwise) of ethanol, or its equivalent, is irritating to the skin, causing dryness and consequent peeling and cracking. Because chapped skin tends to be more susceptible to microbial contamination, repeated use of alcohol disinfectants can exacerbate the very problem they are intended to solve. Second, whereas alcohol can be an effective disinfectant, once it evaporates its antimicrobial activity is lost.
Alcohol-based skin disinfectants which are known in the art, some of which address the two problems mentioned above, include the following.
U.S. Pat. No. 6,107,261 by Taylor et al., issued Aug. 22, 2000, and its continuations-in-part, U.S. Pat. No. 6,204,230 by Taylor et al., issued Mar. 20, 2001 and U.S. Pat. No. 6,136,771 by Taylor et al., issued Oct. 24, 2000, disclose antibacterial compositions which contain an antibacterial agent at a percent saturation of at least 50 percent. The compositions further comprise, as solubility promoters, a surfactant and a hydric solvent, which may be an alcohol.
U.S. Pat. No. 5,776,430 by Osborne et al., issued Jul. 7, 1998, discloses a topical antimicrobial cleaner containing about 0.65-0.85 percent chlorhexidine and about 50-60 percent denatured alcohol, which is scrubbed onto and then rinsed off the skin.
European Patent Application 0604 848 discloses a gel comprising an antimicrobial agent, 40-90 percent by weight of an alcohol, and a polymer and thickening agent.
U.S. Pat. No. 4,956,170 by Lee, issued Sep. 11, 1990 relates to a high alcohol content antimicrobial gel composition which comprises various emollients and a humectant to protect the skin from the drying effects of the alcohol. In alcohol formulations, higher levels of alcohol are needed to provide instant kill against sensitive as well as resistant strains of bacteria.
Certain formulations virtually omit alcohol as a primary antimicrobial agent, such as, for example, the skin sanitizing compositions disclosed in U.S. Pat. No. 6,187,327 by Stack, issued Feb. 13, 2001, which comprises triclosan (2,4,4′-trichloro-2′-hydroxydiphenyl ether; concentration 0.1-0.35 weight percent) in a topical lotion comprised of a surfactant phase and a wax phase, which purportedly provides antimicrobial protection for 3-4 hours after application. The composition prepared according to the claims of U.S. Pat. No. 6,187,327 further comprises chlorhexidine digluconate.
U.S. Pat. No. 5,965,610 by Modak et al., issued Oct. 12, 1999, teaches skin cleaning compositions comprising antimicrobial agents and zinc salts, where zinc salts have a soothing effect on the skin. The claimed subject matter includes formulations comprising a gel formed between zinc gluconate, chlorhexidine gluconate and a solvent, to which various thickening agents, emulsifying agents and/or emollients may be added.
U.S. Pat. No. 5,985,918 by Modak et al., issued Nov. 16, 1999, relates to “Zinc-Based Anti-Irritant Creams”.
U.S. Pat. No. 5,705,532 by Modak et al., issued Jan. 6, 1998, relates to “Triple Antimicrobial Compositions” comprising less than or equal to two percent of a chlorhexidine compound, less than or equal to 0.1 percent of a quaternary ammonium compound, and less than or equal to two percent parachlorometaxylenol.
Octoxyglycerin, sold under the trade name Sensiva® SC50 (Schulke & Mayr), is a glycerol alkyl ether known to be gentle to the skin. Octoxyglycerin exhibits antimicrobial activity against a variety of Gram-positive bacteria associated with perspiration odor, such as Micrococcus luteus, Corynebacterium aquaticum, Corynebacterium flavescens, Corynebacterium callunae, and Corynebacterium nephredi, and is used in various skin deodorant preparations at concentrations between about 0.2 and 3 percent (Sensiva® product literature, Schulke & Mayr).
For example, U.S. Pat. No. 5,885,562 by Lowry et al., issued Mar. 23, 1999, relates to deodorant compositions comprising an antimicrobial agent, namely polyhexamethylene biguanide (at a concentration of between 0.01 and 0.5 percent), together with a polarity modifier such as Sensiva® SC50 (octoxyglycerin), at levels of typically 1-15 percent. Compositions disclosed in U.S. Pat. No. 5,885,562 may further comprise a short chain monohydric alcohol such as ethanol at a level of between 20 and 80 percent. Formulations useful as deodorants, however, would differ from those used as skin sanitizers in that skin sanitizers would optimally exhibit rapid broad spectrum activity against bacteria, fungi, and viruses, not merely gram positive odor causing bacteria.
U.S. Pat. No. 5,516,510 by Beilfuss et al., issued May 14, 1996, discloses deodorant compositions which comprise glycerin monoalkyl ethers such as octoxyglycerin (referred to therein as 2-ethyl hexyl glycerin ether, and as being the most preferred among these compounds). The deodorant compositions of U.S. Pat. No. 5,516,510 may be formulated in aqueous and/or alcoholic solutions and may further comprise additional antimicrobial compounds, including triclosan, chlorhexidine salts, alexidine salts, and phenoxyethanol, among others. Specific concentration ranges for triclosan and the biguanides are not provided.
U.S. Pat. No. 5,951,993 by Scholz et al., issued on Sep. 14, 1999, and U.S. Pat. No. 6,352,701 by Scholz et al., issued Mar. 5, 2002, which is a continuation application thereof, each relate to hydroalcoholic compositions having a lower alcohol and water in a weight ratio of about 35:65 to 100:0, between at least 0.5% and 8.0% by weight thickener system of at least two emulsifiers, wherein each emulsifier is present in at least 0.05% by weight, wherein the composition free of auxiliary thickeners has a viscosity of at least 4000 centipoise at 23° C., and wherein each emulsifier is comprised of at least one hydrophilic group.
U.S. Pat. No. 6,022,551 by Jampani et al., issued Feb. 8, 2000, relates to an antimicrobial alcohol-containing composition containing specified antimicrobial compositions in solution with greater than 30% by volume of alcohol and a carbomer polymer thickener having a viscosity of greater than 9000 centipoise. Optional ingredients further include essential oils, tack modifiers, fragrances, emollients, pH adjusters, viscosity modifiers, transdermal enhancers, sarfactants, dyes, colors and water.
U.S. Pat. No. 5,403,864 by Bruch et al., issued Apr. 4, 1995, relates to alcohol-based solution containing 40-70% by weight of an alcohol or alcohol mixture, antimicrobial compounds such as triclosan and chloroxylenol (PCMX), and optionally includes emollients, surfactants, perfuming agents and chelating agents.
U.S. Pat. No. 4,478,853 by Chausse, issued Oct. 23, 1984, relates to a skin conditioner containing a hydroalcohol gel having from about 35 to 50 percent by weight of a lower alkanol, from about 0.1 to 1 percent by weight of a neutralize gelling agent, wherein the gelling agent is a polyacrylic acid cross-linked with a polyether of an oligosaccharide, and from about 1 to 15 percent by weight of a base composition made of a panthenol moisturizer and an emollient such as a polyhydric alcohol humectant and polyether derivative. The viscosity of these compositions are disclosed to range generally from 2,000 to 20,000 cps.
U.S. Pat. No. 3,485,915 by Gerstein et al., issued Dec. 23, 1969, relates to aqueous and/or alcoholic compositions suitable for topical application to the skin containing, as thickening agents, about 0.1 to about 5 percent by weight of a neutralized carboxy polymer and about 0.1 to about 2 percent by weight of hydroxypropyl cellulose.
A product called Avagard, made by 3M, is commercially available having a combination of emulsifiers, namely Beheneth-10, behenyl alcohol, cetylpalmitate, and diisopropyl dimer dilinoleate with 1% chlorhexidine gluconate solution and 61% ethyl alcohol (w/w).
A product called Prevacare, made by Johnson & Johnson, is commercially available having petrolatum as its active ingredient; water as a vehicle; liposome-building blocks including glycerol distearate, stearate-10, cholesterol, and polysorbate 80; sodium laureth sulfate as a sarfactant; propylene glycol as a moisterizer; and preservatives including diazolidinyl urea, methylparaben, and propylparaben. Prevacare-D is a commercially available product having white petrolatum and dimethicone as active ingredients, and also includes cyclomethicone as an emollient; polyethylene and silica as viscosity builders; mineral oil as a moisturizer/emollient, propylparaben as a preservative and fragrance.
A product called Hibiclens, made by Zeneca Pharmaceuticals, is commercially available having 4 percent chlorhexidine gluconate as its active ingredient. Inactive ingredients include fragrance, isopropyl alcohol, purified water, red #40 and other ingredients not specified in its labelling.
A product called Purell, made by GOJO Industries Inc., is commercially available in four formulations. According to the product literature, the active ingredient in each formulation of Purell is 62 percent ethyl alcohol. Inactive ingredients for Purell 2 in 1 are water, Stearyl Alcohol, Cyclomethicone, C12-15 Alkyl Benzoate, Cetyl Lactate, Cocamidopropyl PG-Dimonium Chloride Phosphate, Glycerin, PEG-4, Propylene Glycol, Tocopheryl Acetate, Aminomethyl Propanol, Carbomer, Styrene/Acrylates Copolymer, Fragrance (Parfum), Diazolidinyl Urea, Iodopropynyl Butylcarbamate, Methylparaben, and Propylparaben; for Purell Original are water, Glycerin, Isopropyl Myristate, Propylene Glycol, Tocopheryl Acetate, Aminomethyl Propanol, Carbomer, and Fragrance (Parfum); for Purell with Aloe are: water, Aloe Barbadensis Leaf Juice, Glycerin, Isopropyl Myristate, Propylene Glycol, Tocopheryl Acetate, Aminomethyl Propanol, Carbomer, Fragrance (Parfum), Blue 1 (CI-42090), Yellow 5 (CI 19140); and for Purell Kid's Own are water, Isopropyl Myristate, Propylene Glycol, Aminomethyl Propanol, Carbomer, Fragrance (Parfum), and Red 33.